That's just about right folks. Except it's not made up of stocks. It's made up of options, derivatives and other financial instruments to mimic it. After trading on the US exchange daily it's gets recalibrated and there is ALWAYS degradation over time. So yes, only for DAY TRADING and maybe an occasional overnigter. Guaranteed to disintigrate over time. And yes, you can make money with it. But NOT if you hold.